JEE Main · Physics · Atoms
Atom Recoil During Emission
JEE Main asked Atom Recoil During Emission 3 times in 3 of the 108 shifts Lumi analysed, in 2021 and 2024. It belongs to Bohr's Atomic Model, in Atoms (Physics). The longest wait between two years asking it was 3 years. In 2024 it came in more than one shift of the same year.
Updated 2026-10-24
- Times asked
- 3
- in 3 shifts
- Years
- 2 of 8
- First asked
- 2021
- last in 2024
- Pattern
- Occasional
- across the analysed shifts
Questions on this idea a shift, by year
2017–2026. Asked in 2021 and 2024. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Physics questions.
Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 0 in 24 shifts · 2023: 0 in 12 shifts · 2024: 2 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.
Shift by shift
Each square is one analysed shift, in date order. Open a filled one for that paper.
How JEE Main framed it
Numerical value is the usual form. Skill tested: multi-step.
- Recoil speed after photon emission
- Recoil effect on emitted wavelength
Difficulty
2 of the 3 questions had a numerical answer.
Every question
All 3 questions
From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.
- 29 Jan 2024, Shift 1 · Q60When a hydrogen atom going from =2 to =1 emits a photon, its recoil speed is . Where = ______. (Use, mass of…MediumNumerical value
- 4 Apr 2024, Shift 1 · Q60A hydrogen atom changes its state from n = 3 to n = 2. Due to recoil, the percentage change in the wave length of emitted light is…HardNumerical value
- 26 Feb 2021, Shift 2 · Q14The recoil speed of a hydrogen atom after it emits a photon in going from n = 5 state to n = 1 state will be :MediumSingle correct
Shifts: 26 Feb 2021, Shift 2, 29 Jan 2024, Shift 1, 4 Apr 2024, Shift 1.
Same topic
Other ideas in Bohr's Atomic Model
Bohr's Atomic Model has 22 ideas JEE Main has asked; 13 of them came up in more than one question. The 12 most asked are below.
- Energy Level Calculations12× · 2026
- Rydberg Formula and Spectra10× · 2026
- Angular Momentum Quantization9× · 2025
- Shortest and Longest Wavelengths8× · 2025
- Bohr Orbit Radius6× · 2025
- Energy Ratios in Bohr Orbits5× · 2024
- Number of Spectral Lines5× · 2024
- Magnetic Field and Dipole Moment2× · 2026
- Scaling for Hydrogenic Ions2× · 2025
- Excitation and Ionization Potentials2× · 2024
- Identifying Atomic Number from Spectra2× · 2024
- Electron Velocity in Orbit2× · 2022